Positive-displacement piston pump and associated delivery control method

A volumetric pump comprising:

• a product metering chamber,
• a metering piston mounted inside said chamber so as to slide between top dead center and bottom dead center,
• a sleeve at least partially delimiting an intake chamber and an exhaust chamber for said product, and
• a product dispenser movable with respect to the sleeve, the product dispenser places the metering chamber alternately into communication with the intake chamber and the exhaust chamber during operation, and the product dispenser temporarily isolates said metering chamber from any communication with said intake and exhaust chambers,
• the movements of said product dispenser and the movements of said metering piston being synchronized so as to obtain a pump cycle comprising the following successive phases:
• an intake phase in which an inlet orifice of said product metering chamber is open and an outlet orifice of said metering chamber is closed, and said metering piston moves from the top dead center until it reaches the bottom dead center,
• a delivery phase in which said inlet orifice remains open and said outlet orifice remains closed, and said metering piston moves from the bottom dead center toward the top dead center,
• a compression phase in which said inlet and outlet orifices are closed so as not to be in communication with said intake and exhaust chambers, and said metering piston continues to move toward the top dead center, and
• an exhaust phase in which said inlet orifice remains closed and said outlet orifice is open, and said metering piston moves until it reaches the top dead center, and
• wherein the volumetric pump further comprises a pressure sensor for measuring a pressure of the product inside the metering chamber, and a control unit that is connected to the pressure sensor and verifies the presence of pressure peaks exhibiting a value greater than or equal to a predetermined pressure threshold during the compression phases:
• wherein, during the compression phase, the outlet valve is held closed until after the presence of the pressure peak is verified.